Exemplary prior work illustrating laser engraving/etching of identification documents is shown in UK patent publications GB 2,240,948and GB 2,132,136, and in PCT publication WO00/43216. The reader is referred to such documents for background.
Identification documents (hereafter “ID documents”) play a critical role in today's society. One example of an ID document is an identification card (“ID card”). ID documents are used on a daily basis—to prove identity, to verify age, to access a secure area, to evidence driving privileges, to cash a check, and so on. Airplane passengers are required to show an ID document during check in, security screening, and prior to boarding their flight. In addition, because we live in an ever-evolving cashless society, ID documents are used to make payments, access an automated teller machine (ATM), debit an account, or make a payment, etc.
Many types of identification cards and documents, such as driving licenses, national or government identification cards, bank cards, credit cards, controlled access cards and smart cards, carry thereon certain items of information which relate to the identity of the bearer. Examples of such information include name, address, birth date, signature and photographic image; the cards or documents may in addition carry other variant data (i.e., data specific to a particular card or document, for example an employee number) and invariant data (i.e., data common to a large number of cards, for example the name of an employer). All of the cards described above will hereinafter be generically referred to as “ID documents”.
FIGS. 1 and 2 illustrate a front view and cross-sectional view (taken along the A-A line), respectively, of an exemplary prior art identification (ID) document 10. In FIG. 1, the prior art ID document 1 includes a photographic image 12, a bar code 14 (which may contain information specific to the person whose image appears in photographic image 12 and/or information that is the same from ID document to ID document), variable personal information 16, such as an address, signature, and/or birthdate, and biometric information 18 associated with the person whose image appears in photographic image 12 (e.g., a fingerprint). Although not illustrated in FIG. 1, the ID document 10 can include a magnetic stripe (which, for example, can be on the rear side (not shown) of the ID document 10), and various security features, such as a security pattern (for example, a printed pattern comprising a tightly printed pattern of finely divided printed and unprinted areas in close proximity to each other, such as a fine-line printed security pattern as is used in the printing of banknote paper, stock certificates, and the like).
Referring to FIG. 2, an ID document 10 comprises a pre-printed core 20 (also referred to as a substrate). In many applications, the core can be a light-colored, opaque material, such as, for example, white polyvinyl chloride (PVC) material that is, for example, about 25 mil thick. The core 20 is laminated with a transparent material, such as clear PVC material 22, which, by way of example, can be about 1-5 mil thick. The composite of the core 20 and clear PVC material 22 form a so-called “card blank” 25 that can be up to about 30 mils thick. Information 26a-c is printed on the card blank 25 using a method such as Dye Diffusion Thermal Transfer (“D2T2”) printing (described further below and also in commonly assigned U.S. Pat. No. 6,066,594, which is incorporated herein by reference.) The information 26a-c can, for example, comprise an indicium or indicia, such as the invariant or nonvarying information common to a large number of identification documents, for example the name and logo of the organization issuing the documents. The information 26a-c may be formed by any known process capable of forming the indicium on the specific core material used.
To protect the information 26a-c that is printed, an additional layer of overlaminate 24 can be coupled to the card blank 25 and printing 26a-c using, for example, 1 mil of adhesive (not shown). The overlaminate 24 can be substantially transparent. Materials suitable for forming such protective layers are known to those skilled in the art of making identification documents and any of the conventional materials may be used provided they have sufficient transparency. Examples of usable materials for overlaminates include biaxially oriented polyester or other optically clear durable plastic film.
The above-described printing techniques are not the only methods for printing information on data carriers such as ID documents. Laser beams, for example can be used for marking, writing, bar coding, etching, and engraving many different types of materials, including plastics. Lasers have been used, for example, to mark plastic materials to create indicia such as bar codes, date codes, part numbers, batch codes, and company logos. Lasers also have been used to engrave or etch very fine patterns into articles that are extremely difficult to replicates.
It will be appreciated that laser engraving or marking generally involves a process of inscribing or engraving a document surface with identification marks, characters, text, tactile marks—including text, patterns, designs (such as decorative or security features), photographs, etc. Some types of thermoplastics, such as polyvinylchloride (PVC), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate (PET), are capable of absorbing laser energy in their native states. Some materials which are transparent to laser energy in their native state, such as polyethylene, may require the addition of one or more additives to be responsive to laser energy.
For additional background, various laser marking and/or engraving techniques are disclosed, e.g., in U.S. Pat. Nos. 6,022,905, 5,298,922, 5,294,774, 5,215,864 and 4,732,410. In addition, U.S. Pat. Nos. 4,816,372, 4,894,110, 5,005,872, 5,977,514, and 6,179,338 describe various implementations for using a laser to print information. All of these patents are incorporated herein in their entirety.
Features and advantages of the present technology are disclosed in the following Detailed Description, which proceeds with reference to the accompanying drawings.
The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the technology. In addition, in the figures, like numbers refer to like elements. Further, throughout this application, laser engraved indicia, information, identification documents, data, etc., may be shown as having a particular cross sectional shape (e.g., rectangular) but that is provided by way of example and illustration only and is not limiting, nor is the shape intended necessarily to represent the actual resultant cross sectional shape that occurs during laser engraving or manufacturing of identification documents.